Probably the best bet is to ask an Openreach engineer nearby, but other than that there is little that can be done without access to BT's backend systems, and knowing your phone number. Perhaps an ISP could do it.
I guess the important question is whether you are on 8 or 22, rather than a direct exchange line. If you put your phone number into this link
, does it come back with any information about fibre (even if it is prefixed with a future date)?